from langchain_core.documents.base import Blob

blob = Blob.from_path("./mew.txt", metadata={"foo": "bar"})

# Blob api
print(blob.encoding)
print(blob.as_bytes())
print(blob.as_string())
print(blob.as_bytes_io)

#blob的元数据
print(blob.metadata)
print(blob.source)